Magnetic coupling device



Sept. 11, 1951 A. VARGA 2,567,863

y MAGNETIC COUPLING DEVICE Filed Sept. 15, 1948 3 SheeS-She:I l

Sept. 11, 1951 A* VARGA MAGNETIC COUPLING DEVICE Filed Sept. 15, 1948 5211/557577 /mvw 7%;

Sept 11, 1951 A. VARGA 2,567,863

MAGNETIC COUPLING DEVICE Filed Sept. l5, 1948 5 Sheets-Shee 5 Patented Sept. 11, 1951 yUNITED STATES PATENT OFFICE MAGNETIC COUPLING DEVICE Andrew Varga, Philadelphia, Pa., assigner to Schutte and 'Koerting Company, Philadelphia, Pa., a corporation of Pennsylvania Application September 15, 194.8., Serial N o. 49,381

1'3 Claims.

I'I'his invention relates to improvements in magnetic Vcoupling devices of a character adapted for use in ilowmeters and like instruments as a medium for connecting the oat or other movable element of the instrument to a suitable indicator leither proximate to Ior remote from the meter installation.

A principal object of the invention is to provide a relatively simple and highly eliicient magnetic coupling ydevice having inherent vability to maintain the coupling intact under all conditions to which it might normally be subjected in the operation of the instrument with which it is associated.

Another object of the invention is to provide a rmagnetic coupling which reduces to a minimum the dead weight imposed `upon the movable element of the meter with which the coupling is associated, thereby preserving the normal sensitivity of the instrument.

Still another object of the invention is to provide a magnetic coupling wherein the operative relation between the magnetically coupled elements remains substantially constant, and to this end the invention fur-ther contemplates an arrangement in which the said elements are free to move in rectilinear parallel paths.

The invention resides further in certain mechanical and structural details hereinafter set forth and illustrated in the attached drawings, wherein; i

Fig. l is a front elevational and partial sectional view showing a magnetic coupling device made in accordance with the invention;

Fig. 2 is a sectional view on the line 2--2 Fig. 1;

Fig. 3 is a perspective view partly in section of the coupling assembly; and

Figs. 4 and 5 are fragmentary perspective views illustrating modicationswithin the scope of the invention.

The embodiment of the invention illustrated in the drawings comprises a casing I within which is housed the magnetic coupling assembly, In the present instance the casing constitutes a support for a lowmeter 2 which may be of conventional or other design, said 'meter including a flow tube 3 connected at the bottom with an inlet duct 4 and at the top with an outlet duct 5 and containing a oat B the position of which within the tube is a factor, for example, of the velocity of the fluid passing through the latter.

Depending from the iloat 6 is a rod "l, and this rod passes downwardly through a cylindrical casing 8 which extends through the bottom of the i Cal 2 II by means of which the screw may be turned in or out of the casing, as may be required. The iner end of the screw forms a stop for the lower end of the rod 'I and limits the extent of the downward movement of the rod in the casing 3.

As shown in Figs. 2 and 3 the lower end of the rod 'I is made hollow for reception of an elongated bar magnet I 2. The lower open end of the rod l through which the magnet is inserted is normally closed by a plug I3 which seals the magnet chamber within the rod and holds the magnet immovably within the rod. It will be noted that the longitudinal axes of the rod and the magnet I2 coincide.

It will be apparent that with this arrangement the movements of the iioat E in the iiowmeter tube 3 will be accompanied by a corresponding longitudinal movement of the rod 'I and of the magnet l2 in the cylindrical casing 8. It will be noted also that the upper end of the tubular casing 8 is positioned in the uid channel of the meter 2 so that the rod I is entirely immersed in said fluid.

Mounted within the casing I is a bracket, the body of which is designated by the reference numeral I4, said bracket having a forwardly extending arm I5 to which is suitably secured a post I6 which parallels the said body. Journaled at its opposite ends in the body I4 and the post IB respectively is a shaft II to which is secured by means of a set screw I8 (see Fig. 2) the cylindrical hub portion I9 of a lever 2l. One end of this lever, which is thus pivotally supported in the bracket for angular movement about the axis of the shaft I1, has a forwardly turned terminal portion 22 in which is secured a threaded rod 23, said rod extending parallel to the body of the lever 2| and supporting a weight 24 which balances the opposite end of the lever 2I and associated elements as hereinafter described. The weight is threaded on the rod 23 for adjustment longitudinally of the latter. The opposite end of the lever 2I has a forwardly extending arm 25 to the outer end of which is pivotally secured a second lever 26. This lever is pivotally connected at its upper end to a link 21 and pivotally secured at 28 to the rear wall of the casing I. The upper end of the lever 26 also carries a balance weight 29 which may be secured in adjusted position longitudinally of the lever by a set screw 3l.

The lower end of the lever 26 is bifurcated as indicated at 32, 33, and each of the bifurcations has threaded therein a screw 34, these screws being in axial alignment with each other and having cone-shaped inner ends, as best shown in Fig. 2, which enter conical recesses in opposite sides of a block 35 and thereby pivotally support the block between the bifurcations 32, 33 of the lever 26. Since the supporting screws 34 engage the upper end of the block 35 the latter is supported in a depending position at the end of the lever 26. v

As shown in Fig. 3, the block 35 has a central vertical recess 36 through which the casing 8 extends, and supported in the block 35 at eachside of this recess is a rod magnet 31. The normal depending position of the block 35 in the bifurcations 32, 33 and the positions of the.vv

Fig. 3.

The front wall of the casing I has a slotted opening 38 closed by a glass plate 39 secured to the inner surface of said wall, as best shown in Fig. 2, said plate having a .suitable scale Il! marked thereon for coaction with a pointer lIZ secured to the block 35 as illustrated in Fig. 3. In this manner the exact position of the magnets 31 with respect to the magnet I2 may be determined, it being noted by .reference to Fig. 1 that the tube3 of the meter is provided `with a scale A3 affording a direct reading vof the position of the float 6 in the tube and, indirectly, of the position at any moment of the magnet I2.

It will be noted that 'with the arrangement described above and by reason of the magnetic changing the normal positional relationship,

laterally, of the magnets I2 and 31 by reason of the pivotal connection of the lever 23 with vthe lever 2I, which as a result of the movement of the lever Z6 is turned about its relatively xed pivot and constrains the end of the lever 25 which carries the block 35 to move in a rectilinear path parallel to the axis of the magnet I2. In other words, the link 21 and lever 2l, in conjunction, guide the Vlever 25 so that its block supporting end movesin a rectilinear path parallel to the path of movement of the magnet I2. Thus the magnets 31 are not only free to movein paths parallel to the path of the magnet I2, but also cannot be diverted from such path. -The magnets are also free to maintain their normal paralF lel relation through angular adjustment of the block 35 on the pivot pins 34, it being noted that the mode of suspension of the block on the pins tends to retain the magnets 31 parallel to the magnet I2 independently of the magnetic coupling.

The movements of the lever ZI are dampened in the present instance by a dashpot 44, shown. in Fig. 3, which comprises a cylinder l5 and a plunger 43 connected by a rod 41 to the leverZI. A vent 48 is provided in the bottom of the cylinder and the effective size of this vent is controllable by means of a valve 49 adjustable through a knurled head 5I.

Means is provided for operatively connecting the lever 2I with a suitable indicator device remote from the flowmeter. Pivotally supported -upon the hub I9 of the lever 2| is an arm- 52 having a segmentaly slotted end portion 53. The

4 slot 54 of this end portion is curved on'an arc of a circle centered in the axis of the shaft I1 and a set screw 55- passes through the slot and is threaded into the lever 2l whereby the arm 52 may be secured to the lever 2| in the desired position of relative angular adjustment. The arm 52 has an extension 56 at the opposite side of the hub I9, said extension being longitudinally slotted as indicated at 51 in Fig. 1, and a flanged plate 58'is secured against the face of the extension 56 by means of a set screw 59 which passes through the slot 51 and is threaded into the plate 58. Secured in the plate 58 is the lower end of a turnbuckle link BI, the upper end of which is connected to an arm 62 of a bell crank lever, the other arm 63 of the lever being operatively connected through a link 64 with a transmission unit 65. This unit, in the present instance, constitutes one element of a transmission train connecting the bell crank lever k52, 63 with the remote indicator device mentioned above. The details of the indicator and of the transmission Vmeans form no part of the present invention and are therefore not illustrated. y

The operation of the device will be apparent from the foregoing description. It will be noted that the device herein described is so constituted that the magnetic coupling is inherently incapable of being broken by sudden surges of liquid in the flowmeter stream and resultant rela tively rapid displacement movements of the iioat in the tube 3. Assuming, for example, that the north pole of the magnet I2 is at its upper end as viewed in the drawings, land the corresponding poles of the magnets 31 at theirlower ends, the magnets are then magnetically coupled by attraction at both ends. If the actuating magnet I2 is suddenly moved upwardly at a rate tending to leave the magnets 31 and associated parts behind, the resulting approach of the south pole of the magnet I2 to the south poles of the magnets 31 will overcome the residual inertia and bring the magnets quickly to the normal coupled positions. The lengths of the magnets in relation to the maximum travel of the float 6 in the tube 3 effectively precludes a condition wherein the magnets are forced by mutual repulsion into uncoupled relation. It `will be noted also that since the magnets 31 are substantially uniformly spaced with respect to the magnet I2 and `are free to move in conformity to the movements of that magnet, as previously set forth, substantially no side thrust is exerted in any direction by the magnets 31 upon the magnet I2. This avoids objectionable frictional loadin-g ofthe float assembly and permits said assembly to move with substantial freedom in the casing.

f It will be apparent that the same functional characteristics can be had by use of more than two of the follower magnets arranged in uniformly spaced relation about the magnet I2. Similar characteristics are also obtainable by use of a single bar magnet of the hollow cylindrical form illustrated in Fig. 4. In this case the two magnets 31 of the earlier described embodiment are replaced by a single magnet 66 of cylindrical form, the latter being mounted on the lever 26, in essentially the same manner as the magnets 31, through the medium of a collar 61 which is attached to the magnet 66 preferably at a point above center of mass of the latter. The magnet 66 embraces the casing 8 and magnet I2 and is free to assume a position coaxial with the latter. The poles of the magnet 66 at the opposite ends of the magnet respectively, are in the same rela;

tion to the magnet l2 as those of the magnets 31.

Similar functional characteristics are also obtainable by use of magnets of a different form, as illustrated for example in Fig. 5. In this case the bar magnets 31 and 66 of the previously described embodiments are replaced by two magnets 68 and 59 of annular form united in axially spaced relation by non-magnetic elements 'll in the form in the present instance of two rods.

The poles of each of the magnets 68 and 69 are on the inner and outer peripheries respectively, i. e., in one the north pole is on the inner circumferential portion and the south pole on the outer circumferential portion, and in the other magnet these positions of the poles are reversed. The magnets coaxially embrace the magnet l2 and are arranged with respect to the poles of that magnet so as to afford the desired coupling.

It will be apparent that plural magnets of annular or possibly other form might, Without departure from the principle of the invention, be substituted also for the bar magnet I2 of the prime mover; and that the assembly as a whole is subject to modification within said principle as dened by the appended claims.

I claim:

1. In a magnetic coupling a pair of bar magnets arranged in magnetically coupled parallel relation, and transmission means including an element operatively connected to' one of said magnets, said magnets being free for movements in parallel paths and in said parallel relation, said transmission element consisting of a floating lever with means for supporting the lever so that the point of connection thereof with the magnet is constrained to move in a path paralleling the path of movement of the first magnet.

2. In a magnetic coupling, a pair of longitudinally movable bar magnets arranged in parallel magnetically coupled relation, and transmission means operatively connected with one of said magnets, said transmission means including a lever pivotally connected at one end to the said magnet and having guide means constraining said one end to move in a path paralleling the path of movement of the other magnet.

3. A magnetic coupling according to claim 2 wherein the guide means includes a second lever pivotally connected to the rst named lever and supported upon a relatively fixed pivot.

4. A magnetic coupling according to claim 3 wherein the second lever constitutes an active link in the transmission train.

5. A magnetic coupling according to claim 3 wherein the second lever is pivotally connected to the first lever at a point intermediate the ends of the latter, and wherein further the outer end of the l-lrst lever is supported for movement in a predetermined path.

6. In a magnetic coupling a pair of longitudinally movable bar magnets arranged in parallel magnetically coupled relation, transmission means operatively connected with one of said magnets, a lever pivotally connected at one end to one of said magnets, a second lever supported on a relatively xed pivot and pivotally connected to the lever rst named, means associated with the first lever for counter-balancing the weight of the magnet with respect to the point of pivotal connection between said levers, and means associated with the second lever for counter-.balancing the weight of the rst lever, the said magnet, and the rst named counter-balancing means, with respect to said relatively fixed pivot.

7. A coupling according to claim 6 wherein the said levers constitute elements of a transmission train.

8. A coupling according to claim 6 wherein the rst named lever has guide means cooperating with the second lever to hold the point of pivotal connection of the first lever With the magnet to movement in a predetermined path.

9. In a magnetic coupling a bar magnet, and a pair of bar magnets at opposite sides respectively of the first named magnet and in parallel magnetically coupled relation to the latter, said magnets being movable as a unit in parallel paths, the magnets of said pair being pivotally supported for self-adjustment into parallelinity with the first named magnet.

10. A magnetic coupling according to claim 9 wherein the magnets of said pair are free to move longitudinally with the other magnet but are constrained against translational movements in lateral direction.

11. In a magnetic coupling, a magnetic prime mover exhibiting spaced north and south poles and movable rectilinearly on a line intersecting both said poles, and a magnetic follower having north and south poles magnetically coupled respectively to the so-uth and north poles of said prime mover and free for movement on a line parallel to the line of movement of said prime mover, the prime mover being in the form of a bar magnet with the opposite poles at the eX- tremities thereof, and the follower consisting of a hollow cylindrical magnet also with the opposite poles at the extremities thereof and embracing and coaxial with the prime mover.

12. In a magnetic coup-ling, a magnetic prime mover exhibiting spaced north and south poles and movable rectilinearly on a line intersecting both poles, and a magnetic follower having north and south poles magnetically coupled respectively to the south and north poles of said prime mover and free for movement on a line parallel to the line of movement of said prime mover, the prime mover comprising a bar magnet and the follower comprising a plurality of annular magnets rigidly connected and presenting opposite poles to the respective poles of the bar magnet.

13. A magnetic coupling according to claim l2 wherein the follower comprises rigidly connected annular magnets embracing and presenting an- D nular opposite poles to the respective magnetic poles of the prime mover.

ANDREW VARGA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 716,110 Rose Dec. 16, 1902 2,182,469 Davis Dec. 5, 1939 2,847,861 Winton May 2, 1944 2,380,399 Bowie July 31, 1945 2,425,691 Brewer Aug. l2, 1947 2,458,759 Abell Jan. 11, 1949 2,475,630 Melas July l2, 1949 FOREIGN PATENTS Number Country Date 20,418 Great Britain of 1892 373,880 Italy July 25, 1939 

